EP2920032B1 - Dashboard crossmember with an integrated airbag and corresponding vehicle - Google Patents

Description

The invention relates to the driving position of a vehicle and more particularly to an integrated airbag dashboard cross member.

In general, the passenger airbag (or airbag) at the front of the vehicle is integrated in a housing which is itself fixed rigidly to the dashboard crossmember of the driving position of the vehicle, this crossmember extending in a direction transverse to the vehicle. This housing contains the gas generator for deploying the airbag bag and has an opening facing upward for deployment of the airbag outside the housing towards the seated passenger facing.

Such an arrangement has the disadvantage of being bulky vertically and in the longitudinal direction of the vehicle. It is thus not possible to lower the height of the dashboard coming from above the cross or to retreat longitudinally towards the front of the vehicle.

In order to gain space along these directions, certain devices provide for the integration of the gas generator with the cross member as described in the document GB2403192 . The box attached to the crossbar then contains only the bag of the airbag. This arrangement however remains bulky vertically and in the longitudinal direction of the vehicle.

In addition, these arrangements require the mounting of a housing on the dashboard crossbar, which is expensive in terms of material, assembly time and represents a significant weight.

We also know via documents DE 195 37 233 A1 which corresponds to the preamble of claim 1, and EP 0796 769 A1 dashboard cross members incorporating airbags and reinforcing inserts. The invention aims to overcome these drawbacks and to propose design alternatives by proposing an integrated safety airbag dashboard cross member having a reduced overall dimensions and vertically in the longitudinal direction of the vehicle. The integration of the airbag to the dashboard crossbar also makes it possible to make the dashboard transom visible at least on the passenger side and to consider the creation of an aesthetic transom for the passenger. The use of a housing is no longer necessary, the assembly crosses / airbag is thus lighter, less expensive, simpler and faster to assemble.

To this end, the object of the invention relates to a dashboard cross member of a motor vehicle according to claim 1. Such an arrangement reduces the overall dimensions of the cross / airbag assembly in the vertical and longitudinal directions of the vehicle. It is thus possible to achieve a very low dashboard vertically and disengaged in the longitudinal direction, providing a feeling of space to the passenger.

Inside the crossbar, the airbag is in a state in which it is folded on itself so as to be able to deploy outside the cross member via the opening. The folding mode used for the airbag is therefore similar to the folding mode usually used, for example when the airbag is placed inside a housing fixed to the crossbar.

Due to the integration with the airbag cross, the cross member according to the invention has an enlarged cross section relative to the existing cross members. The cross member is thus shaped so as to be housed inside the inner cavity of the airbag, in particular in a folded on itself, ready to be deployed. The dimensions of the cross member may therefore vary depending on the dimensions of the airbag to be integrated.

This increase in the cross section is, however, offset by the removal of the housing housing the airbag. Thus, space saving in the vertical direction of at least 60 mm can be achieved.

The shape of the opening may be rectangular or any other form adapted to allow the deployment of the airbag. The dimensions of the opening can thus vary according to the volume of the airbag. For example, a rectangular opening may be 210mm over 100mm.

The crossbar can be made of steel, aluminum or magnesium, its thickness will be determined according to the desired resistance. This thickness is for example of the order of 2 to 5mm.

When the airbag deploys following a shock to the bust of the seated passenger facing, an opposite force is exerted on the dashboard rail. This effort is exerted along a vertical longitudinal plane of the vehicle and has a greater vertical component than the longitudinal component. The crossbar can thus have to withstand thrust forces of 750 kg to 2500kg.

It may be advantageous to strengthen the cross to allow it to support these efforts, which may be required by legislation.

For this purpose, the invention provides for placing one or more reinforcing inserts inside the cavity of the profile on each side of the opening in the longitudinal direction of the cross member and / or at the opening according to the longitudinal direction of the cross. Such reinforcements are most often attached to the profile of the cross. They can be made of steel or any other material providing sufficient strength.

These reinforcing inserts may have an I, H, or polygonal cross-section at at least four sides. Such inserts thus comprise bearing walls which are applied against the inner faces of the profile and connected by connecting walls extending through the cavity. Such support walls are shaped to conform to the inner face of the walls of the profile. The presence of connecting walls extending through the cavity does not always allow to accommodate an airbag between the support walls and support walls can close the opening of the profile. In these cases, the inserts are positioned on either side of the opening along the longitudinal direction of the cross member. The reinforcing inserts are shaped so as to have a shape identical to the shape of the cross and to marry at least partially the inner face of the walls of the profile. An opening may then be provided to correspond to the exit opening of the airbag, which may allow to arrange the insert at this opening in the longitudinal direction of the cross.

As an alternative or in combination with the internal reinforcements, it is also possible to fix one or more external reinforcements at least partly on the outer face of the walls of the profile, on each side of the opening in the longitudinal direction of the cross member and / or at the opening in the longitudinal direction of the cross.

Preferably, such external reinforcements will be disposed on an outer face of the profile opposite to the opening so as not to be seen by the passenger if the cross member is visible.

The profile forming the cross member may have any shape adapted to receive an airbag. In particular, the cross section of the profile may not be constant over the entire length of the profile.

The gas generator for deploying the airbag can be remote from the crossbar.

However, it will preferably be located near the airbag, and more particularly secured to the crossbar.

Advantageously and in a non-limiting manner, the cross-member may thus comprise a gas generator for inflating the airbag housed inside the cavity, this gas generator being fixed on an inner face of the profile situated opposite the opening. . Such an arrangement promotes the deployment of the airbag in the direction of the opening. The gas generator is in fact arranged between the airbag and the profile, against the inner face of a wall of the profile located opposite the opening. In this embodiment, the gas generator is then put in place by the opening of the profile before installation of the airbag.

In another embodiment, the cross member may comprise a gas generator for inflating the airbag located outside the profile, the generator being fixed on an outer face of the profile on the side opposite to the opening, the profile having an orifice for connecting the gas generator to the airbag. The cross section of the profile forming the cross-member can then be reduced with respect to the embodiment in which the gas generator is disposed within the crossbar.

The chosen gas generator will be sized according to the volume of the airbag integrated in the crossbar.

Advantageously and without limitation, a protective element may cover the edges of the opening, this may prevent the airbag from tearing during its deployment. Such a protective element may be in the form of a seal or insert of polymer material covering the edges of the opening, possibly sufficiently rigid to support the closure panel. Advantageously, this closure panel can be made in one piece with the protection element.

The closure panel can be fixed rigidly to the profile all around the opening. It can then also provide a protection function of the edges of the opening. The closure panel then comprises rupture primers for the output of the airbag.

These break primers are, for example, lines of smaller thickness or precut lines formed of dotted cutouts. They can be H-shaped or U-shaped, along the edges of the opening.

Alternatively, the closure panel can be rigidly attached to the profile on only a portion of the periphery of the opening, breakaway primers distributed over the rest of the periphery of the opening allowing the detachment of the closure panel during deployment of the cushion inflatable.

These two variants can also be combined.

This closure panel may be of polymer material or leather, generally of small thickness, for example from 1 to 3 mm thick, preferably from 1 to 2 mm thick.

The invention also relates to a motor vehicle comprising a dashboard cross member according to the invention, the cross member being oriented so that the closure panel is located opposite the bust of a seated passenger, including sitting on a vehicle seat located opposite the dashboard transom.

This vehicle can optionally be arranged so that the closure panel through which the airbag comes out is visible, in other words the dashboard does not cover the cross at the height of the closure panel.

In particular, the dashboard crossmember can be attached to an element of the vehicle body in the longitudinal direction of the vehicle to maintain the crosspiece during the deployment of the airbag. This element of the box is for example the lower rail of bay.

• la figure 1 est une représentation schématique vue de dessus d'une planche de bord de véhicule automobile supportée par une traverse selon l'invention ;
• la figure 2 est une représentation partielle en perspective de la traverse représentée figure 1
• la figure 3 une représentation partielle en perspective de la traverse représentée figure 2, en coupe au niveau de l'ouverture, le panneau de fermeture étant ôté ;
• les figures 4 à 7 sont des représentations schématiques d'une traverse selon l'invention, en coupe suivant un plan XZ et montrant différents types d'inserts de renfort utilisables.

The invention is now described with reference to the appended non-limiting drawings, in which:

• the figure 1 is a schematic representation seen from above of a dashboard of a motor vehicle supported by a cross member according to the invention;
• the figure 2 is a partial representation in perspective of the transom shown figure 1
• the figure 3 a partial representation in perspective of the transom shown figure 2 in section at the opening, the closure panel being removed;
• the Figures 4 to 7 are schematic representations of a cross member according to the invention, in section along an XZ plane and showing different types of reinforcing inserts used.

In the present description, the terms front, rear, upper, lower, refer to the front and rear directions of the vehicle, when the cross member is mounted on the vehicle. The X, Y, Z axes correspond respectively to the longitudinal (front to back), transverse and vertical axis of the vehicle. The longitudinal direction of the crossbar thus corresponds to the transverse direction of the vehicle.

The figure 1 schematically represents a top view of a dashboard 1 of a vehicle, a steering wheel 2 being disposed opposite the left part of the dashboard 1, the steering column 3 being represented symbolically. The dashboard 1 is supported in part by a dashboard cross member 10. This cross member 10 is fixed at its ends to vehicle structural elements, on each side of the vehicle, typically to the front legs or structural members adjacent (not shown).

The dashboard cross member 10 is formed of a profile 11 with a closed profile, the walls of the profile 11 defining an internal cavity 12 ( figures 2-3 ). The terms "internal" and "external" respectively refer to the elements located inside the cavity 12, respectively outside the cavity 12.

According to the invention, an airbag 20 is disposed inside the cavity 12 opposite an opening 14 provided on a wall of the profile 11 (FIG. figure 3 ), this wall being a visible wall from the passenger compartment of the vehicle in the example shown.

A closure panel 15 completely closes the opening 14 ( figures 1-2 ), this closure panel 15 being shaped to allow the deployment of the airbag 20 outside the profile 11. The closure panel 15 is made of polymer material, possibly leather.

In the example shown, the closure panel 15 is fixed rigidly to the profile 11 all around the opening 14. The closure panel 15 comprises breaking primers such as precut lines 15a, 15b formed of cutouts. dashed.

These precut lines are shaped to allow the airbag 20 to exit and are, for example, precut lines 15a situated at a distance from the edges of the opening, for example in the form of a cross as shown in FIG. figure 2 , or in the form of I or H, or any other adapted form, and / or U-shaped precut lines 15b located on at least a part of the periphery of the opening 14 ( figure 2 ).

The edges of the opening 14 will be made to prevent tearing of the airbag 20 during its deployment. This protection can be obtained by a particular machining of the edges, to avoid any sharp edge, or by the establishment of a protective element on these edges, type joint or other.

In an example not shown, the closure panel 15 can also be fixed directly on the edges of the opening 14 which can help protect the airbag during its deployment.

The profile 11 shown on the figures 2 and 3 has a cross section of elliptical shape and the opening 14 has a rectangular shape with rounded corners.

In the example shown, a gas generator 30 for inflating the airbag 20 is located outside the profile 11. gas generator 30 is fixed on an outer face of the profile 11 on the opposite side to the opening 14. It is shown partially on the figure 3 .

The profile 11 has an orifice 16 making it possible to connect the gas generator 30 to the airbag 20. In the example, the gas generator 30 comprises a support 31 inserted in this orifice 16 and fixed to the profile 11, for example by means of screw.

The airbag 20 and its gas generator 30 can be secured to one another and form a module which is then installed inside the crosspiece 10, the gas generator 30 can then be fixed to the profile 11 by being disposed either inside the cavity 12 (not shown) or outside, as shown in FIG. figure 3 . Whatever the embodiment, the gas generator 30 is fixed to the profile 11, for example by screws, rivets, clips, by gluing or any other appropriate means.

Reinforcing inserts may also be arranged inside the cavity 12, secured to the profile 11 by their shape and / or by any appropriate means, for example by gluing, screwing, riveting, welding. The inserts may, in an alternative embodiment not shown, be made by molding in one piece with the body of the profile (aluminum or magnesium profile or a similar alloy).

The Figures 4 to 7 represent different embodiments of these reinforcing inserts.

On the figure 4 , the section 11 shown has an elliptical section, similar to a boat mast, and the reinforcing insert 40 has an I-shaped cross section comprising two bearing walls 41, 42, which are applied against opposite internal faces of the profile 11 and connected by a connecting wall 43 extending through the cavity 12, parallel to the longitudinal direction of the crosspiece 10. The support walls 41, 42 are shaped to conform to the inner face of the profile 11. The connecting wall 43 may be oriented parallel to the direction of deployment of the airbag 20, which may allow better reinforcement in this direction.

Such a reinforcing insert 40 can not be arranged facing the opening 14 which would then be closed by the reinforcing insert. Such reinforcing inserts 40 are then placed on either side of the opening 14 in the longitudinal direction of the crosspiece 10.

On the figure 5 , the section 11 shown has an elliptical section, similar to a boat mast, and the reinforcing insert 50 has a substantially H-shaped cross section. In the example shown, this H-shape is obtained by juxtaposition of two upper portions 50a and lower 50b, secured at the crossbar 53a, 53b of the section H. Each upper portion 50a and lower 50b comprises a portion 54a, 55a; 54b, 55b respectively wings of the section in H connected to a crossbar 53a, 53b respectively. The free edge of each wing 54a, 55a, 54b, 55b comprises a bearing wall 56a, 57a; 56b, 57b, which is applied against an inner face of the profile 11. The bearing walls 56a, 57a of the upper part 50a of the reinforcing insert 50 are substantially opposite the support walls 56b, 57b of the lower part. 50b of the reinforcing insert 50. The bearing walls 56a, 57a, 56b, 57b are shaped to fit the inner face of the profile 11.

In the example shown, the wings of the H-shaped section are not perpendicular to the crossbar 53a, 53b of the H-shaped section, as visible in the figure. This inclination can be chosen so as to improve the resistance of the crossbar to the forces experienced during the deployment of the airbag 20.

Such a reinforcing insert 50 can not be arranged facing the opening 14: there would then be insufficient space to dispose the airbag 20 inside the cavity 12. Such reinforcing inserts 50 are then disposed on either side of the opening 14 in the longitudinal direction of the cross member 10.

On the figure 6 , the section 11 shown has an elliptical section, similar to a boat mast, and the reinforcing insert 60 is shaped so as to have a shape identical to the shape of the cross and to marry at least partly the inner face of the walls of the profile 11.

In this example, the reinforcing insert 60 is an open profile of elliptical shape, the opening of which is arranged to correspond with the opening 14 of the profile 11. figure 6 , the opening 14 is symbolized by a thick line.

As a variant, the reinforcing insert 60 could only be open on a portion corresponding to the opening 14 and be closed on both sides. other of the opening 14 in the longitudinal direction of the crossbar 10.

Of course, the reinforcing insert 60 shown on the figure 6 can also be arranged only on either side of the opening 14 in the longitudinal direction of the crosspiece 10.

In addition, an external reinforcement of shape similar to the shape of the reinforcing insert 60 described with reference to the figure 6 , but secured to the outer face of the profile 11, could be provided to reinforce the cross member 10, possibly in combination with one of the reinforcing inserts described in reference to Figures 4 to 7 .

On the figure 7 , the profile 11 shown has an elliptical section, similar to a boat mast, and the reinforcing insert 70 has a polygonal cross-section with four sides comprising two bearing walls 71, 72, which are applied against opposite internal faces of the profile 11 and connected by two connecting walls 73, 74 extending through the cavity 12 parallel to the longitudinal direction of the crosspiece 10. The bearing walls 71, 72 are shaped to conform to the internal face of the profile 11. The connecting walls 73, 74 may be oriented parallel to the direction of deployment of the airbag 20, which may allow better reinforcement in this direction.

Such a reinforcing insert 70 can not be arranged facing the opening 14 which would then be closed by the reinforcing insert. Such reinforcing inserts 70 are then placed on either side of the opening 14 in the longitudinal direction of the crosspiece 10.

Claims (8)

1. Crossmember (10) of a motor vehicle dashboard (1), this crossmember (10) being formed from a profiled element (11) having a closed profile, the walls of the profiled element (11) defining an inner cavity (12), the crossmember comprising at least one airbag (20) arranged inside the cavity (12) facing an opening (14) formed on a wall of the profiled element (11), characterized in that it comprises a closure panel (15) totally blocking off the said opening (14), this closure panel (15) being configured to allow the deployment of the airbag (20) outside the profiled element (11), and in that the profiled element (11) has an elliptical cross section similar to a boat mast, at least one reinforcing insert (40, 50, 60, 70) being arranged inside the cavity (12) of the profiled element (11) on each side of the opening (14) in the longitudinal direction of the crossmember and/or at the opening (14) in the longitudinal direction of the crossmember, the said at least one reinforcing insert (40, 50, 60, 70) being configured so as to at least in part hug the inner face of the walls of the profiled element (11).
2. Crossmember (10) of a dashboard (1) according to Claim 1, characterized in that the reinforcing insert (40, 50, 70) has an I-shaped or H-shaped cross section or a cross section in the shape of a polygon with at least four sides, and/or in that the reinforcing insert (70) is configured so as to have a shape identical to the shape of the crossmember and to at least in part hug the inner face of the walls of the profiled element.
3. Crossmember (10) of a dashboard (1) according to either of Claims 1 and 2, characterized in that at least one outer reinforcement is fixed at least in part to the outer face of the walls of the profiled element (11) on each side of the opening (14) in the longitudinal direction of the crossmember and/or at the opening (14) in the longitudinal direction of the crossmember.
4. Crossmember (10) of a dashboard (1) according to one of Claims 1 to 3, characterized in that it comprises a gas generator (30) for inflating the airbag (20) housed inside the cavity (12), this gas generator (30) being fixed to an inner face of the profiled element that is situated facing the opening (14).
5. Crossmember (10) of a dashboard (1) according to one of Claims 1 to 3, characterized in that it comprises a gas generator (30) for inflating the airbag (20) situated outside the profiled element (11), the gas generator (30) being fixed to an outer face of the profiled element (11) on the opposite side to the opening (14), the profiled element (11) having an orifice (16) for connecting the gas generator (30) to the airbag (20).
6. Crossmember (10) of a dashboard (1) according to one of Claims 1 to 5, characterized in that a protection element covers the edges of the opening (14).
7. Crossmember (10) of a dashboard (1) according to one of Claims 1 to 6, characterized in that the closure panel (15) is made of polymer material or of leather.
8. Motor vehicle comprising a crossmember (10) of a dashboard according to one of the preceding claims, the dashboard (10) being oriented such that the closure panel (15) is situated facing the chest of a seated passenger.

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